For clinical applications, grafts made of woven, moulded or extruded synthetic polymeric or elastomeric materials are commonly used to replace natural tissue within a living organism which either is diseased or has suffered trauma. Commonly known in the art, grafts are sutured in place during an open surgical procedure or are held in place by stents in a combination known as a stent-graft. Some stent-grafts use barbs to fix the implant into the body conduit but successful stent-grafts can be complex and expensive to manufacture and, because of their rigidity, their use can be restricted to only straightforward surgical cases.
Stent-grafts, whose use now has a several years of history, show a tendency to migrate two to three years after implantation. Such an event currently requires major open surgery to replace the graft.
Other types of flat graft or patches are used to cover tissue damage. These grafts are also sutured or stapled in position during open surgery, but nevertheless also have a tendency to migrate.